ATHENS, Greece — Greece asked the European Union Friday to press member states to speed up the relocation of migrants, after a fire raged through an overcrowded refugee camp, killing two people and seriously hurting two others.

Prime Minister Alexis Tsipras said he was "shocked, as is the entire Greek nation, by the tragic event" that occurred overnight at the Moria camp on the island of Lesbos.

The government said it would seek the faster deployment of promised EU personnel to help process asylum claims. Tsipras' office said he had spoken by phone with European Commission President Jean-Claude Juncker.

A gas canister, used for cooking or heating inside a tent, started the fire, police said. The victims were a young boy and an older woman, who have not been identified.

Another woman and a second child were severely injured and flown by military plane to Athens, where they were hospitalized in serious condition. Several others were less seriously hurt.

Human rights groups strongly condemned the loss of life and blamed it on the intransience and inattentiveness of governments across Europe.

"How many more people need to die in a tent, trying to keep warm, before EU and Greek authorities take action?" said Loic Jaeger, head of mission in Greece for the relief agency Doctors Without Borders, or MSF.

Moria is one of five Greek island camps sheltering refugees and migrants listed for deportation back to Turkey, under a deal struck between the EU and Ankara in March.

More than 62,000 migrants and refugees are stranded in Greece, including nearly 11,500 being restricted to the islands, according to government figures .

Despite the overcrowding, EU member states have accepted fewer than 4 percent of the migrants they are committed to hosting under the bloc's Emergency Relocation Mechanism.

Early Friday, migrants at Moria clashed with police as they were evacuated from the camp during the blaze. The fire was extinguished by firefighters and no arrests were made.

Jaeger of Doctors Without Borders said the insistence of authorities not to move migrants to the Greek mainland had led to the tragedy.

"The fire in Moria is more than an accident. It is a direct consequence of the deplorable living conditions that Greek and EU authorities force refugees to live in inside Moria camp and other places across Greece," he said.